EVENT REVIEW PETplanet Insider Vol. 23 No. 04/22 www.petpla.net 34 tethered closure on such a finish, is to make sure that you can raise the closure from its finish before you begin the articulation of the actual tethering. If you begin articulation too soon, you simply clash with the threads and it’s very difficult for the consumer to open cleanly,” Mark explained. The second closure Mark showed was a hinge-mould-closure (HMC) design. It does not work for CSD products, but is suitable for still beverages, water, and dairy. It is designed for short neck finishes like 29/25. In this closure a “natural tether” is given. It comes with a hinge tension in the design which gives the closure a natural spring effect that stays open over the centre at up to 220 degrees. There is no mechanical hold-back, it stays in that position. The challenge here which was successfully overcome, was to ensure that the cap is fully functioning on an existing threaded 29/25 finish. Mark concluded his presentation with a question: what’s next after tethering? He pointed out that tethering is just one way in which the plastics packaging industry could move towards reducing its environmental impact. He mentioned that a closure design from a single resin type will simplify recycling. In addition, he added that more recycled material should be used and more reusable packaging systems like RefPET bottles should be implemented. Moulds for tethered caps The second speaker was Michael Fink from z-moulds. Michael briefly introduced his company and proudly announced that z-moulds would have a sales and service team in the US from April 2022 on. z-moulds, as a mould making specialist for caps, helps cap designers like Universal Closures, to develop the best design for any tethered cap application. All global testing standards are possible in the approved z-moulds laboratory. Finally, after designing, testing, and developing, z-moulds supports the inline work at its customers’ premises. Michael explained the patented z-slides technology. It differs from other mould systems in the following aspects: the front of the mould has a complete flat parting line. Centring of the cavities is not necessary. The cavities and sliders are located inside the mould. The mould itself is centred with guiding bars; this results in an almost wear-free system. Each cavity is accessible from the front. The entire cavity stack can easily be pulled out so that each part of the cavity can be replaced (eg. core, cooling top, slider). The 70mm frame of the mould stays the same for all kind of closures. It is a completely modular system. Also, the cavity pitch remains the same, and in addition the same hot runner system can be used. New requirements arise for the tethered caps. Michael said that the z-slides technology is still used but it must be extended. The sliders need to be higher, because the parting line for a tethered cap design is moving up. By changing the angles on the demoulding face, where the height is increased to a distance of 15mm, it is possible, for example, to produce a 29/25 closure design entirely on the cold half of the mould. The extended z-slide technology can easily be implemented in the existing z-slides system. The extended z-slides system can be used for closures with an outer diameter of 25-33mm and a cap height in the slider of a maximum of 15mm. Most standard necks like PCO 1881, PCO 1810, 29/25mm and 30/25mm are compatible as well as new neck finishes like 26/22mm, GME 30.37, GME 30.38, GME 30.40, GME 30.41 and 25mm. Michael concluded that all z-moulds technologies like the z-slides, z-slides extended, and the z-folded system are compatible with each other. That means the systems have always the same pitch between the cavity, it is possible to use the same hot runner, and most mould plates are the same. In addition, they have the same mould accessories and last but not least the same cooling system. For Michael, the high flexibility of the systems is also a contribution to sustainability. He concluded: “It is better to use the existing equipment and cover the new requirements by making just simple changes.” Inspect tethered caps The last speaker to take the microphone was Sascha Baumanns. Sascha is Head of Sales at the German-based company Intravis GmbH. With a subsidiary in Atlanta, USA, as well as global service and sales points, Intravis is very well known for its inspection systems for the plastic packaging industry. Sascha pointed out that Intravis systems all over the world inspect an average of about 20,000 beverage closures – every single second. After this impressive statement, Sascha started to present Intravis’ inspection solutions for tethered closures. The new tethered closure designs which focus on compatibility with existing production equipment as well as on high added value in terms of user experience, result in new design features and therefore need new inspection solutions. The first of the three inspection systems presented by Sascha was the CapWatcher Q-Line, with the Q standing for Quality. This system is an inline solution suitable for the inspection behind an injection moulding or compression moulding machine. The CapWatcher Q-Line inspects 100% of the produced closures. The system is equipped with eight cameras, a micro-hole inspection, as well as a special temperature measurement. Altogether, the CapWatcher Q-Line gathers 144,000 cavity related product information every minute which helps to optimise the production process. As one example, Sascha explained, that the temperature measurement of each closure in combination with cavity number reading offers unprecedented possibilities in monitoring the performance of the mould. Sascha went on that a repeatable positioning and separation of the closures is both a fundamental requirement and the key for a reliable inspection. To assure the correct and soft separation, the CapWatcher Q-Line is equipped with a form fitting lateral star wheel. And for the positioning? Intravis now uses a newly developed Artificial Intelligence for its inspection modules which no longer needs a perfectly aligned closure for a properly done inspection. Another important feature is the contactless high-voltage inspection for detecting micro-holes in the injection point. These holes can lead to inconveniences for the end consumer since the bottle becomes leaky or foreign substances enter the bottle. A conventional micro-hole inspection still uses a metal wheel to dip into the closure, making it impossible to inspect fea-
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